BOLOGNA, ITALY. In our first LAF Survey (February 2001) one of the questions related to the circumstances preceding the very first episode of afib. The most common trigger for the first one was emotional or work-related stress (26%) followed by physical overexertion at 24%. Caffeine, alcohol, and ice-cold drinks were next at 10%, 6%, and 8% respectively. A later survey dealt with the triggers of subsequent episodes. Here again, stress and anxiety were high on the list with 94% of adrenergic, 56% of mixed, and 29% of vagal afibbers listing anxiety and emotional and work-related stress as important trigger factors. Caffeine was listed as a trigger for 23% with 31% of adrenergic afibbers experiencing this trigger factor. It is known that both stress and caffeine lead to an increase in sympathetic dominance, so it is not surprising that adrenergic afibbers are particularly vulnerable to stress and caffeine.

A group of Italian researchers now confirm that stressful periods are indeed powerful initiators of a first atrial fibrillation (AF) episode. Their study involved 400 patients (51% men) who presented with a first episode of AF. Their average age was 54 years, and none of them had underlying heart disease. After admission and cardioversion (as needed), the patients were asked how many cups of coffee (espresso) they drank per day and also questioned as to their alcohol and chocolate consumption, smoking habits, physical activity level, and their body mass index (BMI) and waist-to-hip ratio was measured. Finally, all patients underwent a series of cognitive tests to evaluate acute psychological stress during the past 7-30 days. A control group matched for age and gender was selected and evaluated as above.

The researchers found that AF patients had a significantly higher mean life acute stress score (64 LCU) during the week preceding the first episode when compared to the control group (34 LCU). As a matter of fact, the group with a LCU between 75 and 100 had twice the risk of developing afib than did the group with an LCU between 0 and 25. Coffee was another potent trigger with participants drinking more than 3 cups of espresso a day being 3 times more likely to develop afib than were those drinking just 2 cups a day. Obesity (BMI greater than 30) was associated with a relative 61% increase in the risk of experiencing a first afib episode. The researchers found no significant correlations between afib risk and alcohol and chocolate consumption, cigarette smoking, and level of physical activity. They also made the following interesting observations:

• Forty-seven percent of the patients converted spontaneously to normal sinus rhythm within the first 48 hours. Patients with a recent acute stressful event showed the highest probability of spontaneous conversion.
• An increase in coffee consumption was noted in the days after the stressful event and this increase was more pronounced among patients who were not habitual coffee drinkers.

The researchers identify high espresso coffee consumption, a recent acute stressful event, and obesity as independent risk factors for the development of acute lone AF. They also suggest that reducing coffee consumption and avoiding obesity may lead to a reduction in the incidence of AF.

Mattioli, AV, et al. Effect of coffee consumption, lifestyle and acute life stress in the development of acute lone atrial fibrillation. Journal of Cardiovascular Medicine, Vol. 9, No. 8, 2008, pp. 794-98

Editor's comment: The finding that emotional and work-related stress is a trigger factor for afib episodes is not surprising. Nor is it surprising that caffeine was fingered as a culprit. Caffeine consumption results in the release of norepinephrine, the nervous system transmitter that increases sympathetic (adrenergic) activity. Thus adrenergic and mixed afibbers would be vulnerable to over-consumption of caffeine, while it would be expected to affect vagal afibbers much less or not at all. Discussions on the Bulletin Board have produced the suggestion that the AF-promoting effects of coffee may be due to the pesticides it contains rather than to the caffeine as such. It is possible that this may be largely true for vagal afibbers, but I don't believe the caffeine effect can be dismissed as far as adrenergic and mixed afibbers are concerned. Nevertheless, drinking organically-grown coffee would certainly be a prudent measure for all afibbers who regularly indulge.